end caps

[nutpn]

On a 1-1/4 inch tube with .65 thickness- if its gonna be threaded 1-3/16"x20 how much thickness has to to be taken off the id of the tube in order to tap it right, thanks

[apd855]

Basicly none. Scroll down to the calculator and enter your numbers.

http://www.newmantools.com/tapdrill.htm

[nutpn]

On the quide you sent me too, It says for 75% threads on a 1-3/16"×20 tap =1.13876 which is roughly a lil bigger than 1-1/8 which equals 1.1250 and a lil less than the next step up 1-9/64 which equals 1.1406 - So 1-1/8 drill bit would probably do it right, am I right or wrong, thanks for pointing me in the right direction...

[Shift1]

you need to figure out what the depth of thread is for the 20 thread pitch. (.0325)
1.250-.0625=1.1875 (1 3/16)
1.250 OD- .065 - .065 = 1.120 ID
The Double Depth of Thread for 20 tpi is .065
Subtract the double depth of thread from the OD of the thread
OD of thread is 1.1875 (1 3/16) - ddot .065 = 1.1225
1.1225 would be the id of tubing to be threaded
In your example your material ID should be 1.120, based on the figures you supplied. The .0025 is pretty much a non issue for what you want to do.

How are you planning to run the tap? Needs to be straight....

[apd855]

On the quide you sent me too, It says for 75% threads on a 1-3/16"×20 tap =1.13876 which is roughly a lil bigger than 1-1/8 which equals 1.1250 and a lil less than the next step up 1-9/64 which equals 1.1406 - So 1-1/8 drill bit would probably do it right, am I right or wrong, thanks for pointing me in the right direction...

I like a thight thread, I went with 90 on the calculator. I single point everything, so I just use the calc. as a guide and adjust on the fly.

[nutpn]

Ok thanks, and thats gonna be the next problem is getting the threads straight

[CMV]

As soon as you figure out that problem your next is probably be how to hold the tube. the tap will want to spin the tube more than cut threads - esp w/ 316. I think it will be a challenge for you to figure out how to hold it tight enough that the tube doesn't spin once the full-size teeth start to engage, but not deform the tube walls. It won't go easy - even at 20 tpi.

[Bendersquint]

I would say pass on the tap, far too much chance of it not working right or damaging your tube.

Why not cut the threads via single point?

[nutpn]

I would like to get a piece of titanium, thanks for all your help and advice

[CMV]

When you find someone willing to trade SS for Ti let me know. I've got tons of SS I'll trade

All joking aside - you're going to compound your problems even further moving to Ti. You should be moving the other direction to 6061 aluminum, 1020 DOM, or 4140. Depending on your application & for the methods you're wanting to use to make it, you're going to have to use something that machines easier, not harder.

What exactly are you trying to make and what specific tools do you have available?

[Bendersquint]

I would like to use titanium tube, I have some 1-1/4 inch .065 stainless but I would like to find someone that has some extra titanium and swap with them, thanks for all your help and advice

PM sent about some Ti shorts we have.

[mollinst]

"PM sent about some Ti shorts we have."

Man! They've got to be uncomfortable as hell...

[Bendersquint]

"PM sent about some Ti shorts we have."

Man! They've got to be uncomfortable as hell...

You have no idea!




Don't weigh much though and no need to was them just go to the blast cabinet!

[nutpn]

[quote="Bendersquint"][quote="nutpn"]I would like to use titanium tube, I have some 1-1/4 inch .065 stainless but I would like to find someone that has some extra titanium and swap with them, thanks for all your help and advice[/quote, thankyou

[Historian]

"PM sent about some Ti shorts we have."

Man! They've got to be uncomfortable as hell...

Thank you for the uplifting chuckle this dreary evening. Well done.

I had to STEEL myself before I entertained the image of our dear friend
Mr. B. dressed as the TIN Man.

As the Medici* with their famous logo once said: "It takes a pair of BRASS BALLS
to pun around a man with a sword.

Best.

* << http://italian.about.com/library/weekly/aa091599a.htm >>